Optical magnetometers are used for the accurate measurement of magnetic fields. These magnetometers utilize a phenomenon known as Larmor precession, in which metal atom spins have a precession at a frequency proportional to the ambient magnetic field. The atoms are optically pumped by a pump laser beam, and their spin rotation frequency is measured by a probe laser beam. Usually, these magnetometers are used to measure absolute values of certain magnetic fields in a controlled environment and thus, they are often magnetically shielded to avoid the effect of external interferences (e.g. the earth's magnetic field). They are also commonly big and expensive, due to the laser components and shielding they comprise.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the figures.